1. Field of the Invention
The present invention relates to a knocking writing utensil such as a ball-point pen, a mechanical pencil, or a marker, that uses a knocking operation to move a writing medium to a forward position in which the tip of the writing medium protrudes from the tip of an external cylinder.
2. Description of the Related Art
A conventional knocking writing utensil includes an external cylinder, a writing medium inserted and housed in the external cylinder so as to be moved in the axial direction, an elastic body for urging the writing medium rearward, a clip with its proximal end fixed to the external cylinder, and a knock body that is exposed outwardly from the external cylinder to be easily knocked (e.g., actuated, depressed, etc.). The knock body is operated to move the writing medium from a withdrawn position within the external cylinder to a forward position where the writing medium tip protrudes from the tip of the external cylinder.
If a user forgets to withdraw the writing medium into the external cylinder and clips the conventional writing utensil to the edge of their jacket pocket for instance, then the writing medium may stain their clothing or make a hole therein.
A knocking writing utensil that solves this problem is described in the applicant""s Japanese Utility Model Publication No. 5-25915 and Japanese Utility Model Publication No. 6-15735.
In these knocking writing utensils, a clip is integrated with a knock body protruding from the rear end portion of an external cylinder. An engagingly-locking protrusion is provided on the rear surface of the tip of the clip so as to engage an engaging-lock receiving portion formed on the external cylinder to hold a writing medium at a forward position.
In this knocking writing utensil, when the user attempts to separate the tip of the clip from the external cylinder, in order to insert the clip on a pocket, the engagingly-locking protrusion is disengaged from the engaging-lock receiving portion to automatically withdraw the writing medium. This prevents a garment, and an attached pocket, from being stained or damaged. However, since the clip moves in response to the knocking of the knock body, knocking the knock body is impossible while the clip is in a gripping position. Thus, with this type of writing utensil, a knocking operation is difficult.
Furthermore, to return the writing medium to the withdrawn position, both ends of the clip must be rocked up and down, and the knocking operation of the knock body does not allow the writing medium to return to its housed (withdrawn) position. Thus, different operations are required to extend the writing medium and to withdraw it. Therefore, another problem is that the operation of withdrawing the writing medium and the knocking operation are not simple, but instead are unduly complicated.
In view of the foregoing and other problems, disadvantages, and drawbacks of the conventional knocking writing utensil, an object of the present invention is to provide a knocking writing utensil that facilitates a simple knocking operation and that enables the writing medium to automatically return to a withdrawn position when the clip is used.
To attain the above and other objects, a knocking writing utensil according to the invention, includes an external cylinder, a writing medium inserted and housed in the external cylinder so as to be movable in the axial direction, an elastic body for propelling the writing medium rearward, and a knock body that protrudes from the external cylinder to be knocked. In a knocking operation, the knock body is knocked (e.g., actuated, depressed, etc.) to move the writing medium between a withdrawn position within the external cylinder and a forward position where the writing medium tip protrudes from the tip of the external cylinder.
In the writing utensil, an engagement body for positioning the writing medium is preferably provided within the external cylinder. The engagement body has an engagingly-locking protrusion formed thereon. An engaging-lock receiving protruding portion, including an engaging-lock receiving portion at its front end, is formed on a back surface of a non-proximal end of a clip having its proximal end fixed to the external cylinder.
The external cylinder has a guide hole formed to correspond to the engaging-lock receiving protruding portion of the clip. The guide hole preferably is wider than the engaging-lock receiving protruding portion in only one lateral side of the hole relative to the engaging-lock receiving protruding portion.
The engagingly-locking protrusion of the engagement body engages the engaging-lock receiving portion of the clip through the guide hole to hold the writing medium at the forward position. The engagingly-locking protrusion disengages from the engaging-lock receiving portion and is placed behind the engaging-lock receiving protruding portion to hold the writing medium at the withdrawal position.
In the writing utensil, a knock bar is disposed inside the external cylinder. The knock bar is integratedly operated with the knock body, and has a cam portion that can be engaged with the engagement body.
The cam portion guides the engagingly-locking protrusion beyond the engaging-lock receiving protruding portion, from behind it, to the engaging-lock receiving portion. The cam portion also guides the engagingly-locking protrusion from the engaging-lock receiving portion to a position behind the engaging-lock receiving protruding portion, so as to pass by one lateral side of the engaging-lock receiving protruding portion.
In a writing operation, when the knock body is operated, the cam portion of the knock bar, integratedly operated with the knock body, engages the engagement body, to press the engagingly-locking protrusion of the engagement body forward against the resisting force of the elastic body.
The cam portion of the knock bar moves the engagingly-locking protrusion from behind, beyond the engaging-lock receiving protruding portion of the clip to the engaging-lock receiving portion located at the front end of the engaging-lock receiving protruding portion.
In this manner, the engagingly-locking protrusion engages with the engaging-lock receiving portion to hold the writing medium at the forward position such that its tip protrudes from the tip of the external cylinder. Thus, writing is possible.
When not writing, the knock body is operated again to make the cam portion of the knock bar engage with the engaging body so that, based on the urging force of the cam portion and elastic body, the engagingly-locking protrusion is moved from the engaging-lock receiving portion to behind the engaging-lock receiving protruding portion so as to bypass the engaging-lock receiving protruding portion.
Then, the engagingly-locking protrusion is disengaged from the engaging-lock receiving portion and placed behind the engaging-lock receiving protruding portion to hold the writing medium at the withdrawal position at which it is withdrawn into the external cylinder.
Optionally, the cam portion of the knock bar can engage the engagingly-locking protrusion of the engagement body. The cam portion of the knock bar has a first cam surface that guides the engagingly-locking protrusion from behind to a position beyond the engaging-lock receiving protruding portion to the engaging-lock receiving portion. The cam portion of the knock bar also has a second cam surface that guides the engagingly-locking protrusion from the engaging-lock receiving portion to behind the engaging-lock receiving protruding portion in an operation to pass by one lateral side of the engaging-lock receiving protruding portion. The first and second cam surfaces of the cam portion of the knock bar reliably guide the engagingly-locking protrusion through a predetermined route to prevent malfunction.
Optionally, besides the engagingly-locking protrusion, a cam receiving portion that engages with the cam portion of the knock bar can be formed on the engagement body. Since the cam receiving portion, as well as the engagingly-locking protrusion, are formed on the engagement body, the cam portion of the knock bar can stably guide the engagement body.
A knocking writing utensil according to another aspect of the present invention includes an external cylinder, a writing medium inserted and housed in the external cylinder so as to be moved in the axial direction, an elastic body for urging the writing medium rearward, and a knock body that is exposed outwardly from the side of the external cylinder to be knocked. The knock body is operated to move the writing medium between a withdrawn position in which it is withdrawn into the external cylinder and a forward position in which the writing medium tip protrudes from the tip of the external cylinder.
In the writing utensil, an engagement body, coupled to the writing medium to position it, is provided in the external cylinder and has an engagingly-lock protrusion formed thereon. An engaging-lock receiving protruding portion, having an engaging-lock receiving portion at its front end, is formed on a back surface of a non-proximal end of a clip having its proximal end fixed to the external cylinder.
The external cylinder has a guide hole formed therein corresponding to the engaging-lock receiving protruding portion of the clip. The guide hole is wider than the engaging-lock receiving protruding portion in only one lateral side of the hole relative to the engaging-lock receiving protruding portion. The guide hole has, at a front end opposed to the engaging-lock receiving portion, a front-end cam surface that gradually approaches a side where the engaging-lock receiving protruding portion does not exist, toward the front end of the cam surface.
The engagingly-locking protrusion is engaged with the engaging-lock receiving portion through the guide hole to hold the writing medium at the forward position, and is disengaged from the engaging-lock receiving portion and placed behind the engaging-lock receiving protruding portion to hold the writing medium in the withdrawal position.
The knock body is adapted to being knocked to move the writing medium forward, located at the withdrawal position, against the resisting force of the elastic body and also, to move the engagingly-locking protrusion beyond the engaging-lock receiving protruding portion, from behind it to the engaging-lock receiving portion.
Further, the knock body is adapted to being knocked to move the writing medium forward, from its location at the forward position, thereby causing the engagingly-locking protrusion to depart from the engaging-lock receiving portion and then to slide on the front-end cam surface. As a result, the engagingly-locking protrusion moves to a position behind the engaging-lock receiving protruding portion passing by one lateral side of the engaging-lock receiving protruding portion.
The knock body is operated to move the writing medium forward, from its location at the withdrawal position, against the resisting force of the elastic body. This moves the engagingly-locking protrusion of the engagement body, coupled to the writing medium, beyond the engaging-lock receiving protruding portion of the clip from behind it to the engaging-lock receiving portion installed at the front end of the engaging-lock receiving protruding portion. In this manner, the engagingly-locking protrusion is engaged with the engaging-lock receiving portion to hold the writing medium at the forward position where its tip protrudes from the tip of the external cylinder. Thus, writing is possible.
The knock body is operated to move the writing medium, from its location at the forward position, in a forward direction to cause the engagingly-locking protrusion to depart from the engaging-lock receiving portion and then to slide on the front-end cam surface. This moves the engagingly-locking protrusion to behind the engaging-lock receiving protruding portion so as to bypass the engaging-lock receiving protruding portion. In this manner, the engagingly-locking protrusion is disengaged from the engaging-lock receiving portion and is placed behind the engaging-lock receiving protruding portion, to hold the writing medium at the withdrawal position at which it is withdrawn into the external cylinder.
The engagement body may have a slit for bending the engagingly-locking protrusion in the direction of the inner diameter.
Upon interfering with (e.g., abutting) the engaging-lock receiving protruding portion of the clip, the engagingly-locking protrusion can be bent in the direction of the inner diameter to bypass the engagingly-lock receiving protruding portion and to move to the front side of the engagingly-lock receiving protruding portion. Then, the operator feels resistance through the knock body to confirm this operation, resulting in improved operability.
The engaging-lock receiving protruding portion may have at its rear an inclined surface (see FIG. 4(c), reference numeral 28c) that is inclined such that its height gradually decreases toward its rear end, and the engagingly-locking protrusion may have at its top an inclined surface (see FIG. 3(a), reference numeral 26c) that is inclined so that its height gradually decreases toward its frond end.
When the engagingly-locking protrusion contacts the engagingly-locking receiving protruding portion of the clip, the inclined surfaces of the engaging-lock receiving protruding portion and engagingly-locking protrusion slide across each other while being in contact to smoothly move the engagingly-locking protrusion beyond the engaging-lock receiving protruding portion.
The present disclosure relates to subject matter contained in Japanese Patent Application No. Hei 10-211655 and Japanese Patent Application No. Hei 11-190931, filed Jul. 27, 1998, and Jul. 5, 1999, respectively, which are expressly incorporated herein by reference in their entirety.